Whether it was at his family home in Scituate or on Nantucket -- the island he called paradise -- the 27-year-old loved being by the ocean, his close friend Michael Greeley said.

Early Saturday morning, when Griffin was out with friends on the island, he dove off the top of the “Juice Guys” building on Straight Wharf into the harbor and apparently drowned, according to police.

“Corey was an unbelievably motivated young professional with friends all over the country,” Greeley said. “Nobody could have asked for a better friend, a better brother to his brother Michael and sister Casey, or a better son.”

At 2 a.m., police responded to 44 Straight Wharf for a report of a man missing in the harbor.

Nantucket lifeguard Colin Perry, who was off-duty at the time, happened to be working nearby and was called to the scene. Perry made several dives and recovered Griffin from the ocean bottom, police said.

Officers administered CPR at the scene and the Nantucket Fire Department took Griffin to Cottage Hospital where he was pronounced dead at 3 a.m.

Romina Mateza, an employee at Nantucket Ice Cream & Smoothies, which is located in the building that Griffin jumped from, said it used to be common for young kids to dive into the water from the roof, but she hasn’t seen anyone else do it this summer and she doesn’t think anyone has ever drowned in the past.

The shingle sided harbor-front shack is located on the Straight Wharf marina in the downtown area of Nantucket.

In a conference call Saturday, family friends described Griffin as a driven and successful businessman, exceptional hockey player, and a generous soul with a passion for giving back to the community.

The young man recently left his job at Bain Capital Ventures LLC in Boston for a position at a risk management company in New York City.

Stephen Greeley, Michael’s father, speaking as a spokesman for the Griffin family, said the young man was on the island to attend the The Nantucket Boys & Girls Club Tim Russert Summer Groove concert and to raise money for amyotrophic lateral sclerosis on behalf of his friend Pete Frates.

Frates, whose battle with ALS recently turned the ice bucket challenge into a viral social media campaign, met Griffin in 2006 at Boston College and the two have been friends since.

“He was an absolutely outstanding young business professional and rising star,” said Bryan Koop, another close friend of the Griffin family. “He had an uncommon maturity, for his age, for giving back. He would say how blessed he felt for having such giving family.”

Griffin’s father, Robert, is the president of the New England Area for Cushman & Wakefield real estate company. He is also founder of the annual Boston Children’s Hospital fundraiser “Champions for Children’s.”

Several years ago, the younger Griffin launched The NHL Alumni Pro-Am, a charity hockey tournament which also benefits Boston Children’s Hospital.

He and his father are both committee members.

“The Griffin family has a long-standing relationship with Boston Children’s,” Michael Greeley said.

It is unclear why Griffin was at the harbor and what the circumstances were that led to his apparent drowning, according to Cape and Islands District Attorney Michael O’Keefe, whose office is investigating the death along with Nantucket police.

“It’s a tragic event. People just have to be very careful when doing these kinds of things,” O’Keefe said referring to diving off the building into the harbor. “It’s obviously not the wisest thing in the world.”